Reversible brush-holder for dynamos.



J. L. CREVELING. REVERSIBLE BRUSH HOLDER FOR DYNAMOS. APPLICATION FILED AUG. 29, 1911.

1 ,109,901 Patentegi Sept. 8, 1914.

WIT/E8858 UNITED STATES PATENT OFFICE.

JOHN L. CREVELING, OF NEW YORK, N. Y., ASSIGNOR '10 SAFETY CAR HEATING AND LIGHTING COMPANY, A CORPORATION OF NEW JERSEY.

Specification of Letters Patent.

Application filed August 29, 1911. Serial No. 846,850.

To all whom it may concern:

, Be it known that I, JOHN L. CREVELING a resident of New York, in the county an State of New York, have invented wrtain new and useful Improvements in Reversible Brush-Holders for Dynamos, as set forth in the annexed specification and drawing forming a part thereof.

My invention pertains to that class of dynamos in which the armature is subject to reversals in direction of rotation and has for its principal object to provide means whereby the current delivered by a dynamo will remain of constant polarity regardless of reversals in direction of rotation of the armature.

In the drawing Figure 1 represents a partial longitudinal section and elevation of a dynamo comprehending my invention. Fig. 2 is'an enlarged detail, in plan, ofthe yielding stop mechanism and a part of one of the arms which carry the commutator brushes.

Referring to the drawing, particularly Fig. 1, 1 represents an armature provided with the usual commutator 2, carried by the shaft 3 supported as by the usual journals one of which is shown at t carried by the casting 5 provided with the flanged portion 6 attached to the usual field frame 7 as by means of screws 8. The commutator is provided with the usual brushes carried by the brush-holders 9 in turn sup ported by the arms 10 carried by thering, or casting 11, of iron, or other magnetic material provided on each side with annuiar steel ball-races 13 as indicated adapted to re ceive the balls 12 which are held between said races by annular flanges 14 and 15 secured together. These flanges 14 and 15 are preferably made of non-magnetic material and fitted upon the hub or extension 16 in such manner as to be free to rotate thereupon. The springs 17 tend to move the flanges and brush holders andbrushes in a right-handed direction while the limit of motion that may be given the same by the springs is determined by the stops, or members, 18. 19 represents anannular magnet frame which may be cast integral with the flanged portion 6 if desired and is provided with a winding 20 which may be placed in shunt across the brushes ,as indicated. It will be obvious that if the armature be revolved in one direction or the other the friction of the brushes upon the commutator will cause the ring 11 to revolve and allow the brushes to revolve with the commutator until such revo- 1u t1on is arrested and I provide the rin 11 with stops 21 which engage the bolt 22 carried within the member 23 and pressed outwardly ihto the position shown in Fig.

2 as by the spring 24. The member 23 is held yieldingly in position as by the screws 25 and springs 26 in an obvious manner.

The operation of my dynamo is substantially as follows: If the armature be revolved in such direction that' the upper portion be moving in a direction toward the observer, the brushes will revolve with the commutator until in the positions shown Patented Sept. 8, 1914. i

in Fig. 1 when the stop 21 will engage the bolt 22 and further revolution of the ring or casting l1 and brush holders and brushes carried thereby will be arrested, and the stops are so located that when revolving in this direction, the brushes are properly placed at opposite ends of the axis of commutation. lf now the generator armature revolve at suflicient speed that its electromotive force be appreciable, or sufiicient to be useful, the winding 20 will become'energized and the electromagnet 19-20 will attract the ring 11 and firmly hold the same in a definite fixed position and the brushes will be securely held in their proper posi tions by the said magnet; thus chattering of the brushes or other vibration will cease, and wear on the ball races will be avoided,

the bearing members will not be subjected to the strain or vibration. it now the generator stop, its electromotive force will become nil and the magnet 1920 will release the ring 11 and the springs 17 will press the same into the position shown in Fig. 1, and the brushes will be free to revolve in case the armature revolve in an opposite direction. If now the armature be revolved in the opposite direction, the brushes and ring 11 will revolve until the lower brush is in the osition occupied by the upper brush in Flg. l and the lower stop 21 engages the bolt 22, and' it will be obvious that by properly spacin' the stops 21 the brushes Wlll. have their re ative positions reversed with re ards the axis of commutation and, there ore, the current do livered by the generator to line will remain uniform. Upon sufficient speedof revolution to cause the electromotive force to be appreciable the magnet 19-20 will again attract the ring 11 and hold the same firmly in ition. It will be noted, referring particuearly to Fig. 2, that the bolt 22 is held by a fixed stop and thus the s ock upon the.

brush holders and brushes will be greatly lessened. It will also be noted that inasmuch as a bi-polar machine is shown, the stops 21 are so spaced as to allow the brush holders and brushes to revolve a full 180 degrees, while if a. multi-polar machine used, the stops, of course, will be so spaced as to allow the brushes to travel through the proper arc and if it be desiredto further rotate the brush holders and brushes beyond the positions determined by the stops as, for example, to examine the same or replace the brushes, the bolt 22. may be pressed back against the spring 24 in an obvious manner and release the stop 21 and allow revolution of the ring 11 for this purpose. The brushes may, of course, be con-' nected to line by the usual flexible leads or in any other deslred manner. It will be seen from the above'description, therefore, that the springs 26 allow the stop 22 to yield bodily in either direction, or laterally with respect to itself, while the spring 24 holds this stop 22 in position to project far enough to. be engaged by the projections 21 on the ring 11.

I make no claim herein to the broad idea of means ofa rigid stop coiiperating with the brushes to retard their-rotation at pre-.

determined points, nor to electromagnetic means for holding the brushes at the points of arrest, norto the idea of means of holding the rotatable means controlled by the current generated by the machine, as these various features of invention are made the subject of my application filed Aug. 7 1911, Serial No. 642,582. Nor do I claim herein the idea of means of a yielding stop and independent means for holding the brushes at extremes of movement, nor magnetic means for restraining the brush-holders, nor antifrictionalmeans broadly for sup orting the brush-carriers, as such features 0 my invention are made the subject of my application filed Aug. 19, 1911, Serial No. 644,983.

I do not wish in any way to limit myself to the details of construction or exact mode of o eration set forth in this specification whic illustrates one ty e of dynamo embodyin the essentials of my invention, for it is o vious that wide departure may be made in the way of details without departing from the spirit and scope of'my invention which is as set forth in the following claims:

areaooi.

' I claim said means comprising means also rotatable with the armature for holding the firstnamed means stationary, both means being movable in the direction of the axis of the armature.

2. In a dynamo electric machine an armature, means for maintaining the current flow always in the same direction for reversals of rotation of said armature, said means being adapted to rotate therewith; said means comprising magnetizable means also rotatable with the armature for holding the first-named means stationary so as to avoid chattering, both means being movable in the direction of the axis of the armature.

3. In a dynamo electric machine an armature, means for. maintaining the current flow always in the same direction for reversals of rotation of said armature, said means being adapted to rotate therewith; said means comprising magnetizable means also rotatable with the armature, and electromagnetic means for holding the magnetizable means stationary so as to avoid chatterin said magnetizable means being also mova Is in the' direction of the axis of the armature.

4-. In a dynamo electric machine an armature, means for maintalning the current flow always in the same direction for reversals of rotation of said armature, said means being adapted to rotate therewith; said means comprising magnetizable means also rotatable with the armature, said means being movable in the direction of the axis thereof; one or more stops for restraining said magnetizable means, and electromagnetic means for holding the magnetizable means stationary so as to avoid chattering.

5. A dynamo having an armature, acommutator and brushes therefor, means for holding said brushes in operative relation to said commutator, means for rotatably supporting said holding means whereby the same may be rotated comprising bearin means located, upon opposite sides of sai supporting means, and magnetic means cooperating therewith.

6. The combination in agenerator having an armature, a commutator and brushes in operative relation therewith, means for holding said brushes comprising a rotatable member, bearing members located on opposite sides thereof for supporting the same, and electro magnetic means for holding said rotatable member.

7. In a dynamo having an armature, a

commutator and brushes 1n operative relabrushes comprehending a rotatable member, a bearing member for supporting the same, yielding means tending to hold said bearing member in such position as to allow said rotatable member to rotate, and means for moving said rotatable member out of the rotating position.

8. In a dynamo having an armature, a commutator and brushes in operative relation therewith, means for holding said brushes comprehending a rotatable member, a bearing member for supporting .the same, yielding means tending to hold said bearing member in position to allow said rotatable member to rotate, and electro magnetic means for moving the rotatable member out of rotatable'position.

9. In a generator having an armature a commutator and brushes in operative relation therewith, rotatable holding means for said brushes, and yielding checking or restraining means located in the path of the holding means, said checking means being provided with means for normally forcing the same into the path of the holding means.

10. A dynamo having an armature, a commutator, brushes cooperating therewith, means capable of rotation for holding said brushes, and means for arresting said rotation comprising a laterally yielding stop and yielding means for holding the same in I operative position.

11. In a dynamo electric machine, an arangle with respect mature, means for maintaining the current flow always in the direction of rotation of said armature, said means being adapted to rotate with the armature through a certain angle; and means for producing movement of the said first-named means in the direction of the axis of said armature to secure the said means in certain ositions.

l2. In a dynamo electric machine, an armature, a brush-holder, means supporting the brush-holder to enable the same to rotate with the armature through a certain angle, and for also allowing the brushholder to move in the direction of the axis of the armature; and means for producing such axial movement to secure the brushholder in operative position.

13. In a dynamo electric machine, the combination of a commutator and a shaft bearing adjacent the same; a bearing member carried by said bearing and comprising a pair of ball races, a plurality of brushholders carrying current collecting'devices coope 'ating with said armature; and means for supporting said brush-holders received between said ball races, whereby said supporting means can rotate through a certain to the commutator.

' JOHN L. CBEVEIEJING- Witnesses: M. E. HILLOCK, CnAs. McC. CHAPMAN. 

